Tuberculin Purified Protein Derivative (PPD)

Tuberculin purified protein derivative (PPD) is a sterile, aqueous solution containing a purified protein fraction derived from the culture filtrates of a human strain of *Mycobacterium tuberculosis*. It is used primarily as an intradermal diagnostic antigen in the Mantoux tuberculin skin test to aid in the detection of infection with *M. tuberculosis*, which causes tuberculosis (TB). PPD does not have a discrete chemical structure, as it is a mixture of proteins rather than a single defined molecule.

Other names

Tuberculin, Purified Protein DerivativeAplisolMantouxTubersolSclavo PPD Soln

Tuberculin PPD elicits a delayed-type hypersensitivity reaction mediated by cell-mediated immunity. Sensitized antigen-specific T lymphocytes recognize mycobacterial antigens presented via MHC class II molecules on local antigen-presenting cells, leading to cytokine release and recruitment of additional immune cells at the site. This response typically becomes evident within 48–72 hours.